The objective of this study is to assess the efficacy of antibiotic ointment prophylaxis to reduce incidence of corneal ulceration and subsequent blindness. We compare communities randomized to receive an intensive health promotion effort aimed at early prophylaxis for corneal abrasion to communities receiving standard-of care (no active intervention). Corneal ulceration is a leading cause of blindness globally, and once infection is present it is difficult to substantially improve visual potential of the eye. Individully randomized controlled trials have been unsuccessful at demonstrating large differences in clinical outcomes with different antimicrobial or adjunctive therapies. Prospective cohort studies have suggested that antibiotic prophylaxis Is effective at reducing corneal ulceration, but a community randomized clinical trial is necessary to provide definitive evidence of the efficacy of interventions with antibiotic prophylaxis at the community level. We expect that this study will provide an evidence base for such an intervention through the following specific aims: 1) to determine if antibiotic prophylaxis after corneal abrasion reduces the incidence of corneal ulceration in a community randomized trial. 2) To assess the costs and cost-effectiveness of a preventative intervention for microbial keratitis. 3) To determine the incidence of corneal ulceration and abrasion in this district of Taml Nadu, India. No community-randomized trial has ever been performed for microbial keratitis. These trials are difficult to conduct, because of infrastructure and logistical requirements as wel as ethical considerations. We address this by building on our collaborations between the University of California, San Francisco and the Aravind Eye Hospital in Madurai, India. Aravind has an existing infrastructure of community outreach and vision centers that will allow for this study to be completed at a large scale. Patients in control communities will receive treatment should they seek it, as it would be unethical not to provide treatment, but these communities will not receive active health promotion activities. If proven to be effective, this study will provide definitive evidence on a cost-effective, scalable intervention that could substantially reduce the burden of blindness particularly in rural communities in the developing world.